When it comes to tennis balls there are a number of questions that players, coaches and teachers frequently ask. Whether it’s relating to ball sizes, colours, materials or types, it’s important to know what the best tennis ball is for your specific needs.

With that in mind we’ve created this comprehensive guide to tennis balls that covers a number of tennis ball FAQs. Having a greater understanding of what to look for when buying tennis balls will ensure you invest in the right tennis ball for you - something that is vital to ensuring maximum performance and enjoyment whilst playing.

What are tennis balls made of?

Modern tennis balls are made using rubber, pressurised gas, synthetic felt and glue.

The manufacturing process is usually initiated by moulding together the two halves of rubber to form the inner shell or sphere of the ball that provides its shape. The inner shell is then injected with pressurised gas and nylon felt is added to the exterior to complete the tennis ball.

To comply with ITF regulations, tennis balls should bounce between 53 inches and 58 inches, when dropped onto a concrete floor from a height of 100 inches. To achieve this level of bounce, tennis balls will typically have a PSI of 25 - 27.

Early real tennis balls, made in the 1500s were made with leather and stuffed tightly with wool.

What colour is a tennis ball?

The ITF states that tennis balls should be yellow or white. Tennis balls used in regulated tournaments will normally use balls that are “optic yellow” in colour. For graphic designers and colour aficionados “optic yellow” has a hex code of #ccff00 and is also referred to as “fluorescent yellow” or “electric lime”.

It wasn’t until the early 1970s that yellow tennis balls were used. Before 1972, the majority of tennis balls were black or white. It is said that yellow tennis balls were used initially, so that people viewing matches on colour TVs could easily see them. However, yellow tennis balls weren’t used at Wimbledon until 1986.

Tennis balls designed for kids are often distinguished with red, orange and green markings. These balls are lighter and often larger than senior balls.

Why are tennis balls fuzzy?

When a tennis ball has even a small amount of fuzz, it influences the aerodynamics of the ball. When tennis players are about to serve, they will sometimes examine several balls looking for one which has the fuzz or fluff lying as flat as possible. This is because balls with the flattest or least amount of fuzz, will tend to travel faster.

Balls are designed to always have at least a small amount of fuzz on them to prevent the ball from travelling too fast. If professional players were able to serve any faster, it would quickly become impossible for players on the opposite side of the net to return the ball.

In addition to slowing the ball down slightly, the fuzz is said to add more grip and traction when it is hit with the strings of a tennis racket. This traction allows for more control on shots and the ability to add more spin when required. The fuzz can also add a more consistent bounce to the ball and can increase the ball's longevity.

Pressurised vs pressureless tennis balls

Pressurised tennis balls are injected with gas to increase the internal pressure and make them bounce. On the other hand, pressureless tennis balls rely solely on the rubber inner shell to generate bounce.

Pressurised tennis balls tend to be the balls that are opened up in a can. Pressurised balls are used extensively in the US, but in the UK and Europe, both pressurised and pressureless balls are commonly used for practice and recreational matches.

Pressurised tennis balls are used in professional tournaments, but the main issue or complaint about these tennis balls is that they go “dead” and lose their bounce relatively quickly. Generally speaking, pressurised tennis balls generate more spin than pressureless tennis balls, so if you want to replicate the feel of a professional tournament ball in training, then you may wish to invest in a set of pressurised tennis balls.

The two lists below, summarise the pros and cons of pressurised and pressureless tennis balls:

Pressurised Tennis Balls

• Used in ITF tournaments
• Replicate the spin and performance of balls used in professional matches
• Ideal for serious players who want to practice with regulation balls
• Typically lose their bounce faster than pressureless balls

Pressureless Tennis Balls

• Maintain bounce efficiently and can last for years
• More cost-effective
• Ideal for frequent training or practice sessions
• Great for ball machines
• Great for recreational matches
• Better for the environment
• Don’t perform exactly the same as an ITF tour balls

For recreational use many players and coaches choose to use pressureless balls because of the benefits outlined above. Others however, including higher level players, will always utilise pressurised balls as they deliver the same performance as the balls that are used in competitive matches and tournaments.

Why are tennis balls sealed in a can?

If you are a tennis player or coach, you are no doubt familiar with the oddly satisfying noise that occurs when opening a new can of pressurised tennis balls. This noise is caused by the pressure being released from the can when the lid is opened - but why are the cans pressurised?

Pressurised tennis balls need to be sealed in a pressurised can to prevent any air from leaking out of the ball whilst it is waiting to be used. The ambient air pressure (normal air pressure) is 14.7 psi, whilst the pressure inside a typical pressurised tennis ball is 25-27 psi.

Without a pressurised container, the balls inside would slowly lose pressure themselves and once opened, wouldn’t bounce or perform as intended. The pressurised cans ensure that tennis balls can be kept in warehouses and shop shelves for weeks or even months without the balls performance being affected.

Different types of tennis balls

Although tennis balls used in competitive senior matches and tournaments, tend to be the same size, weight and colour, there are still several different types of tennis balls that you should be aware of. The best tennis balls to suit your individual needs will depend on your budget, age, the standard of play and the type of court you will be using.

Kids tennis balls

Back in the 1990s, tennis coaches and teachers would typically use old tennis balls to introduce kids to the game. The old tennis balls would tend to bounce lower, which proved much more practical than brand new balls which would bounce too high. For example, it would often prove difficult teaching kids forehands and backhands, with balls that bounced to their head-height or above!

In more recent years, standardised tennis balls have been developed, specifically for children of different ages to use. Tennis balls designed for kids are bigger, yet lighter than senior balls and bounce lower. Kids’ tennis balls also tend to travel through the air at a much slower speed, making them easier to hit and return.

The table below summarises the recommended tennis ball specifications per age group:

AGE	STAGE	BALL DIAMETER	BALL COLOUR
8 and Under	3	7.5cm	Red
8 & 9	2	6.0 - 6.8cm	Orange
9 & 10	1	6.54 - 6.86cm	Green
10 and above	Senior	6.54 - 6.86cm	Yellow

For children aged 4-8, Vermont have created a range of Mini Red Tennis Balls. These kids tennis balls are larger, lighter and slower through the air than senior tennis balls. They also bounce lower so it is easier for children to hit groundstrokes. If your child is under 8 years old, they can also use the Vermont ITF Approved Foam Tennis Balls. Available in two sizes, they are made from high-density foam which makes them much lighter and easier to hit than regular balls.

Vermont Mini Orange Tennis Balls [Stage 2] are ideal for mini tennis players aged 8 & 9 years of age. These balls are 50% softer and significantly lighter than adult regulation tennis balls.

Vermont Mini Green Tennis Balls [Stage 1] are designed for players aged 10 and are typically used in the final stage of mini tennis. They are 75% compressed, which makes them slower than senior tennis balls.

Other tennis ball FAQs

When should you replace tennis balls?

At the start of a professional match, 2 new cans of balls are normally opened. At Wimbledon and other Grand Slam tournaments, new balls are introduced at the conclusion of the first seven games and thereafter, at the conclusion of every ninth game. The balls are changed regularly in professional matches, to ensure that they are in perfect shape.

Pressurised tennis balls can become frayed (especially when hit exceptionally hard by professionals) and this fraying impacts the flight and the bounce of the ball. As tennis is often a game of inches, it is important that the balls perform and act as consistently as possible.

If you are playing tennis on a recreational basis, how often you decide to change tennis balls is more down to the discretion of the individual players, and the available budget. Whilst professionals change balls numerous times during a match, amateur players might look to test the bounce, squeeze and even the sound of the balls after each use to gauge whether or not they need to be replaced. A visual inspection of the ball for any fraying is also a good idea.

If one ball bounces significantly lower than the others, or when compared to a new ball, you may want to replace it. If the ball starts making a different noise when you are playing this is also a good indication that it has broken down to some extent or become less pressurised. Finally, if it is relatively easy to squeeze the ball it’s probably time to replace that ball with a new one.

Pressureless training tennis balls last much longer than pressurised balls. As pressureless balls rely more on the rubber shell to create the bounce than the air inside, they can last for years depending on how often they are used and how they are stored.

What tennis ball accessories can you buy?

Once you’ve chosen the most suitable tennis balls, you may wish to invest in some tennis ball accessories.

Tennis ball pick-up tubes are extremely handy and practical. Allowing you to clear up a tennis court in a matter of minutes, our tennis ball pick-up tube holds up to 15 balls at a time. With rubber locking straps, you can quickly pick up tennis balls after playing/coaching without having to bend over each time.

If you are a tennis coach or run a tennis court and you need to collect and store large quantities of balls we have various tennis ball mowers and carts in different sizes and specifications to suit all requirements and budgets.

Finally, if you want to take your tennis training intensity to the next level, a tennis ball machine or tennis ball launcher is a wise investment. The Baseliner Slam Tennis Ball Machine serves balls up to 40mph and has an adjustable trajectory so you can serve the balls at different heights and angles.

Can you recycle tennis balls?

Tennis balls can’t be recycled at home, for example in a specific recycling bin, however, there are a small number of UK-based organisations that you can take or send your balls to. For example, there is a company based in Brentford, Middlesex that collects tennis balls and distributes them to dog charities and rescue homes. If you don’t live near Middlesex, you can always look to contact a local dog home or charity and ask if you can donate your tennis balls.

There is also another London-based organisation that will collect tennis balls from local tennis clubs and courts and pay a small amount to the club per ball.

You can also get creative (at your own risk) and use an old tennis ball with a hole or slice cut into it, for a cable tie, a trailer hitch cover, bird-feeder, or attach the ball to the end of a hammer to create a makeshift mallet.

Where can I buy tennis balls?

At Net World Sports, we supply a comprehensive range of ITF approved tennis balls. From tour tennis balls that offer an elite performance on all court surfaces to pressureless training balls and kids’ mini tennis balls - you’re sure to find exactly what you need. If you’re looking to buy tennis balls in bulk we have you covered as all of our Vermont tennis balls can be purchased in large quantities.